Abstract

Former smokers are at increased risk for cardiovascular disease. We hypothesized that dietary aronia polyphenols would reduce biomarkers of cardiovascular disease risk, inflammation, and oxidative stress in former smokers. We also determined the extent these effects were associated with polyphenol bioavailability. A 12-week, randomized, placebo-controlled trial was conducted in 49 healthy adult former smokers (n = 24/placebo, n = 25/aronia) to evaluate if daily consumption of 500 mg aronia extract modulated plasma lipids, blood pressure, biomarkers of inflammation and oxidative stress, and lipid transport genes of peripheral blood mononuclear cells. The primary outcome was change in low-density lipoprotein cholesterol (LDL-C) from baseline, and multivariate correlation analysis was performed to determine if changes in lipids were associated with urinary polyphenol excretion. Aronia consumption reduced fasting plasma total cholesterol by 8% (P = .0140), LDL-C by 11% (P = .0285), and LDL receptor protein in peripheral blood mononuclear cells (P = .0036) at 12 weeks compared with the placebo group. Positive changes in the urinary polyphenol metabolites peonidin-3-O-galactoside, 3-(4-hydroxyphenyl) propionic acid, and unmetabolized anthocyanin cyanidin-3-O-galactoside were associated with lower plasma total cholesterol and LDL-C in the aronia group. Aronia consumption did not change blood pressure or biomarkers of inflammation and oxidative stress. Aronia polyphenols reduced total and LDL-C in former smokers but did not improve biomarkers of oxidative stress and chronic inflammation. The cholesterol-lowering activity of aronia extract was most closely associated with urinary levels of cyanidin-3-O-galactoside and peonidin-3-O-galactoside, its methylated metabolite. This trial was registered at ClinicalTrials.gov as NCT01541826.